A liquid crystal alignment film used to align liquid crystal molecules in a certain direction is applied in various fields. As a liquid crystal alignment film, a photo-alignment film serving as a surface treated by radiation of light and capable of aligning adjacent liquid crystal molecules is used. Conventionally, the photo-alignment film may be manufactured by orientationally ordering a photosensitive material by radiating light, for example, linearly polarized light, to a layer of the photosensitive material.
To radiate the linearly polarized light to the photo-alignment film, various kinds of polarized light splitting elements may be used.
For example, as the polarized light splitting element, a polarized light splitting element using aluminum is disclosed in Korean Patent Application Publication No. 2002-0035587 (Reference 1).
Also, in general, the polarized light splitting element for polarizing light in a UV region may have a linear grid pattern with a pitch of 120 nm or less.